<template>
	<view>
		<!-- 使用自定义组件 -->
		<!-- <my-search :bgcolor="'#000000'" :radius="3"></my-search> -->
		<my-search @click="gotoSearch"></my-search>
		
		<view class="scroll-view-container">
			<!-- 左侧 -->
			<scroll-view class="left-scroll-view" scroll-y="true" :style="{height: wh + 'px'}">
				<block v-for="(item, i) in cateList" :key="i">
					<view :class="['left-scroll-view-item', i === active ? 'active' : '']" @click="activeChanged(i)">{{item.cat_name}}</view>
				</block>
			</scroll-view>
			
			<!-- 右侧 -->
			<scroll-view class="right-scroll-view" scroll-y="true" :style="{height: wh + 'px'}" :scroll-top="scrollTop">
				<!-- 二级分类 -->
				<view class="cata-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
					<view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
					<!-- 动态渲染三级分类的列表数据 -->
					<view class="cate-lv3-list">
						<view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3" @click="getGoodsList(item3)">
							<image :src="item3.cat_icon" mode=""></image>
							<text>{{item3.cat_name}}</text>
						</view>
					</view>
				</view>
				
			</scroll-view>
		</view>
	</view>
</template>

<script>
	export default {
		data() {
			return {
				// 窗口的可用高度 = 屏幕高度 - navigationBar高度 - tabBar 高度
				wh:0,
				//分类信息
				cateList: [],
				//二级分类信息
				cateLevel2: [],
				active: 0,
				//用于滚动到顶部
				scrollTop: 0
			};
		},
		onLoad() {
			//或取到设备的信息
			const sysInfo = uni.getSystemInfoSync()
			//这里会出现一个bug，还需要减去搜索栏的高度 this.wh = sysInfo.windowHeight 
			this.wh = sysInfo.windowHeight - 50
			//调用分类信息的方法
			this.getCateList()
		},
		methods: {
			async getCateList() {
				const {data: res} =  await uni.$http.get('/api/public/v1/categories')
				if(res.meta.status !== 200) return uni.$showMsg()
				
				this.cateList = res.message
				
				//二级分类
				this.cateLevel2 = res.message[0].children
			},
			activeChanged(i) {
				this.active = i
				
				//点击一级分类获取二级分类信息
				this.cateLevel2 = this.cateList[i].children
				
				// this.scrollTop = 0 如果一致是一样的值时无法滚动到顶部
				this.scrollTop = this.scrollTop == 0 ? 1 : 0
			},
			//点击跳转到列表页
			getGoodsList(item3) {
				uni.navigateTo({
					url: '../../subpkg/goods_list/goods_list?cid=' + item3.cat_id
				})
			},
			//搜索
			gotoSearch() {
				uni.navigateTo({
					url:'../../subpkg/search/search'
				})
			}
		}
	}
</script>

<style lang="scss">
	.scroll-view-container{
		display: flex;
		
		.left-scroll-view{
			width: 120px;
			
			.left-scroll-view-item{
				background-color: #f0f0f0;
				font-size: 12px;
				text-align: center;
				line-height: 60px;
				
				&.active{
					background-color: #FFFFFF;
					position: relative;
					&::before{
						position: absolute;
						left: 0;
						top: 50%;
						//可以居中
						transform: translateY(-50%);
						content: '';
						display: block;
						width: 3px;
						height: 30px;
						background-color: #C00000;
					}
				}
			}
		}
		.cate-lv2-title{
			font-size: 12px;
			font-weight: bold;
			text-align: center;
			padding: 15px 0;
		}
		
		.cate-lv3-list{
			display: flex;
			flex-wrap: wrap;
			.cate-lv3-item{
				width: 33.33%;
				display: flex;
				justify-content: space-around;
				align-items: center;
				flex-direction: column;
				margin-bottom: 10px;
				
				image{
					width: 60px;
					height: 60px;
				}
				text{
					font-size: 12px;
				}
			}
		}
		
		
	}
</style>
